Pfizer says the South African variant could significantly reduce vaccine protection

(Reuters) – Laboratory study suggests that the South African variant of the coronavirus could reduce protection against the Pfizer Inc / BioNTech SE vaccine by two – thirds, and it is unclear whether the bullet will be effective against the store, the companies said Wednesday.

The study found that the vaccine was still able to neutralize the virus and there is still no evidence from experiments in humans that the variant reduces the protection of the vaccine, the companies said.

However, they are making investments and talking to regulators about developing an updated version of their mRNA vaccine or boosting bullets, if needed.

For the study, scientists from the companies and the University of Texas Medical Branch (UTMB) developed an engineered virus that contained the same mutations carried on the spike portion of the highly contagious coronavirus variant found first in South Africa, known as B.1.351. The spike, used by the virus to enter human cells, is the main target of many COVID-19 vaccines.

Researchers tested the engineered virus against blood taken from people who received the vaccine, and found a two-thirds reduction in the level of neutral antibodies compared to its effect on the vaccine. most common version of the virus that was common in U.S. trials.

Their findings were published in the New England Journal of Medicine (NEJM).

As there is no established standard yet for determining the level of antibodies needed to protect against the virus, it is unclear whether that two – thirds reduction will make the vaccine ineffective against the variability that is spreading throughout the world.

However, UTMB professor and study co-author Pei-Yong Shi said he believes the Pfizer vaccine is likely to be immune to the opposite.

“We don’t know the minimum number of nests. We do not have that cut-off line, ”he said, adding that he suspects that the immune response seen is much higher than where it needs to be to provide protection.

That’s because in clinical trials, both a Pfizer / BioNTech vaccine and a Moderna Inc-like bullet provided some protection after a single dose with a lower antibody response than the reduced levels caused by the South African variant. in the laboratory study.

Even if the anxious variant significantly reduces efficacy, the vaccine should still help protect against serious disease and death, he noted. Health experts have said it is the most important factor in keeping health care systems stretched from gaining the upper hand.

More work is needed to understand whether the vaccine works against the South African strain, Shi said, including clinical trials and the development of a protective relationship – the criteria to determine what are the levels of protection.

Pfizer and BioNTech said they were doing similar laboratory work to understand whether their vaccine is effective against other variants first discovered in Brazil.

Moderna released letters in NEJM on Wednesday with similar data previously published elsewhere that showed hexagonal antibody levels were falling against the South African variable.

Moderna also said the true effectiveness of his vaccine against the South African variety has not yet been proven. The company has previously said it believes the vaccine will work against the variant.